If fried rice and tteokbokki had a love child, it might taste a lot like this quick, perky rice cake stir-fry. Made in the style of fried rice, rice cakes bring a satisfying pillowy chew. Rice cakes come in several shapes — sliced flat ovals, longer cylindrical segments or even chewy, gnocchi-shaped pieces — and any of them will work for this recipe. A boon to any freezer, frozen mixed vegetables bring instant color and healthy heartiness. Designed as a meat-free alternative to oyster sauce (and sometimes labeled as vegetarian mushroom oyster sauce), vegetarian stir-fry sauce is a glossy brown sauce with a rich umami flavor that is available from Chinese or Asian grocery stores. It brings subtle savory-sweet notes and shines here. Bulk this recipe up by adding crumbled tofu or more veggies.